1. Field of the Invention
The present invention pertains to a substantially dimensionally stable, calendered vinyl film, which has good chemical resistance and outdoor durability, and which is useful as a marking film or decal substrate on the exterior surfaces of vehicles, such as railroad cars, automobiles, trucks, and the like, and other objects where outdoor marking is desirable, such as on gasoline pumps, railroad and highway signs, and the like.
2. Description of the Prior Art
Vinyl films formed by a film casting technique have been used as outdoor marking films. In film casting the plastic raw materials are first dissolved in a suitable solvent or solvents, after which the liquid material is spread out over polished drums or smooth belts which continuously convey the formed film through suitable curing chambers where the solvents are evaporated and recovered. Such products, however, have a number of drawbacks. They are expensive to make and can be ripped or torn if the person applying them to the desired object is not careful because of their generally low tear strength. Commercial cast films currently on the market are also rather thin having a thickness of about 2 mils which render their application to a desired article rather difficult.
Calendered films, although possessing many advantages, are not dimensionally stable. Thus, if one desires to print a multi-colored decal design on said films by means of a plurality of monochromatic printing steps, the film will shrink after each printing operation so that the various colors in the design will not be in proper registry when the printing operation is completed.